Heparin is a very complicated glycosaminoglycan composed of alternating sequences of differently sulfated residues of uronic acid and .alpha.-D-glucosamine linked by .alpha. and .beta. (1-4) bonds. Due to the complexity of its primary structure, heparin is a polydisperse heteropolysaccharide which is strongly heterogeneous in terms of molecular weight, physico-chemical properties and biological activities.
Heparin has been used for already a long time as an anticoagulant and antithrombotic agent in the treatment and prevention of venous thrombosis. It is present in a variety of animal tissues and may be obtained by isolation therefrom. Currently a large part of the heparin used for these purposes is isolated from porcine intestinal mucosa. The isolation process involves hydrolysis of the mucosa followed by extraction of the heparin.
U.S. Pat. No. 5,607,840, hereby included by reference, describes a process for hydrolysis of mucosa tissue. The method involves hydrolysis of an aqueous mixture containing mammalian mucosa with a proteolytic enzyme at a temperature of about 55.degree. C., adsorption of polyanions to an anion exchange resin and subsequent recovery of the anions from the resin and the protein hydrolysate from the digested aqueous solution. In order to stabilize the raw mucosa material and to prevent bacterial growth, salts in the form of an oxygen scavenger or bacteriocides are introduced into the solution.
The heparin content in the mucosa-containing aqueous medium is very low and consequently large amounts of mucosa tissue have to be processed. Therefore, for economic reasons, the hydrolysis process is carried out in reaction vessels of more than 50 m.sup.3. During the reaction time the temperature is kept at a constant level for more than 24 hours and the mixture is stirred vigorously using advanced equipment.
Usually heparin extraction plants are not located at a short distance from the slaughterhouses where the mucosa is collected and transportation over long distances is required. Especially in remote areas this results in a delivery of low quality material at the production plant and an increase of costs.